Movable stairway



March-4, v1930. F, E BESSLER 1,749,409

MOVABLE 'sTAIRwAY Filed Feb. l5, 1928 A 3 Sheets-Sheet 1 Maag-42H22 f W @im fw!! "1M mi *1) vf uw if); l@ 1- 57 l I* Il" WI( WW2 UIL "limp N im@ 144 f 55 55 4 5 447 @T154 42;' 2f; @53551224 d i? /.6 2

4 z f5 @V120 ff? 45 i f7 l@ @i ,i 9 I 51 73 i ll .A 57 El '65049 56' i@ 65 4 if 5i r '56 VvE/V727@ "'1 MWJMQ March 4,' 1930.

F. E. BESSLER MOVABLE STAIRWAY Filed Feb. 13,

1928 5 Sheets-Sheet 2 March 4, 1930.

F. E. BESSLER MOVABLE STAIRWAY Patented Mar. 4, 1930 rUNITED STATES llA'FEIhVl OFFICE FRANK E. BESSLER, OF AKRON, OHIO,ASSIGNOR T0 THE BESSLER DISAPPEAEING STAIRWY COMPANY, OF AKRON, OHIO, A kCORPORATION 0F OHL'O MOVABLE STAIRWAY Application filed February 13, 1928.

panel and a stairway which is mounted for reciprocation longitudinally of said panel.

The main objects of this invention are to provide a steel stairway ofthe type above referred to which is adapted for concrete or other buildings usually classed yas ireproof; to provide counterbalancing tension devices 'which' will be suitable fora steel stairway and panel andvwhich will afford proper balance for these parts; to provide two separate tensioning devices, one tension device for 4counterbalanciiig the weight of thepanel and another distinct and separate tension device for counterbalancing the stairway; to provide means permitting separate adjustment of the tension of either the panel or stairway Vcounterbalancing device without affecting the tension of the counterbalancing device of the other part; to provide an arrangement of lparts which will permit the' selection of one strength of tension device for the panel and a different strength of tension device for the stairway ;V to provide a compact arrangement ofthe tension devices so as toeifecteconomy of'space; to provide an improved method of mounting the tension devices so as to produce a rigidconstruction; to sov mount the te-nsion devices as to facilitate assembling and re- A'moval for inspection or repairs; to provide to be removed without the other; and to pro- Vvide improved rollin@ supports, guides and stops for a steel disappearing stairway.

VFurther objects and advantages of this invention will appear from the following description and claims, considered in connection withfthe accompanying drawings. i IHh'Ihe-iainnexe'd drawingsand theA following Serial No. 253,811.

description set forth in vdetail certain means embodying my invention, said disclosed means, however, constituting but one of the forms in which the principle of my invention maybe applied.

In said annexed drawings:

Figure l is a vertical sectional View of a disappearing stairway and panel embodying my invention and showing the stairway and panel in the lowered position, this view being taken in the planes indicated by the line 1 1, Figure 2;

Figure 2 is a top plan view of the parts Vshown in Figure l;

Figure 3 is a view similar to Figure 1 but showing the panel in the up position and the stairway in the up and concealed position, this view being taken substantially from the planes indicated by line 3 3, Figure 4;

Figure l is a top plan view of the parts yshown in Figure 3;

f Figure 5 is an enlarged view of a portion of Figure 4, this view being confined to showing the counterbalancing tension devices and other parts associated therewith on one side 'of the stairway, the upper side as shown in Figure ll; Y

Figure 6 is a side elevation of the parts shown in Figure 5, this View being taken from the plane indicated by line 6-*6, Figure 5; f y v Figure 7 is a cro'sssectioiial view taken in the planes indicated vby line -7, Figures 3 and 6; f f

Figure 8 is a cross-sectional view through one lof the counterbalancing tension devices, the view being taken inv the'plane indicated yby line .8-8, Figure 6;

Figure 9 is a longitudinal-sectional View through one of the counterbalancing tension devices showing the method of mounting the 'springs therein;

Figure 10 isa fragmentary plan sectional view throughv the axis of one of the drums, this view being taken in the plane indicated y line 10-10, Figure 8;

Figure ll is a fragmentary side elevational view of a portionof one of the plates of the assembly illustrated in Figures 5 and 6;V

Figure 12 is a detachedview of one ofthe end plates used in connection with the mounting of the counterbalancing tension devices;

Figure 13 is a sectiontaken in the plane indicated by line 13-13, Figure 6, this Aview showing an elevation of the adjustable hinge for supporting the panel; i

Figure 14 is an enlarged view of a portion of Figure 1, showing the upper rolling support, guides and stops for the steel stairway;

Figure 15 is a plan view taken from the planes indicated by the inclined line 15-15, Figure 14;

Figure 16 is a fragmentary sectional view looking upward, taken in the plane indicated by the line 16-16, Figure 14;

Figure 17 is an enlarged viewof a portion of Figure 1, showing the lower rolling support and guidesfor the steel stairway; andk Figure 18 isa fragmentary sectional View looking upward, taken in the plane indicated by the line 18-18, Figure 17.

vReferring to the annexed drawings in which the saine parts are indica-ted bythe same respective numerals in the several views, a ceiling 1 of a room is provided with a-suitable opening 2, leading to the attic this opening having a frame 3 consisting of upper i low axle 26. The length of this axle is equal .and lower metal angles 4, and plates 5 and i side plates 6. In contact with one of the end plates 5 adjacent the side plates 6 are mounted two hanger plates 7 which are provided with flanges 8 at their upper ends, said flanges being secured to an upper angle 4 by means of screws 9, as clearly shown in Figures 5 and 6. These hanger plates are provided withV flanges 10 near their lower ends in which are suspended two screws 11, Figures 6 and 13. These screws have threadedl engagement with a hinge 12 which is guided in recess 13 formed in the lower end of the hanger plate 7. hinged support for one end of the panel 15. The opposite end of this panel is supported by means to be hereinafter described. These screws 11 are used for purposes of adjustment in erection, primarily so as to provide means for varying the distance from the hinge pin 14 to the flange 8 at the top of the hanger plate 7 to accommodate possible variations in thickness of the ceiling 1. This provision of adjustment is ynecessary because it is essential that the lower face of the panel 15 should be Vflush with the ceiling 1. It is to be understood that the screws 11 are to be used for adjusting the `height of the hinges-during erection andthat,

after the hinges have been properly located,

they are secured to the end plate 5 'of they traine 3 by means of screws 16 as clearly shown in Figures 6 and 13.

A longitudina'llyeextending plate 17 for sup porting one side of certain :tension devices .is mounted in contact 4with .each of :the side The hinges 12 constitute a plates 6 and is secured to the same by means of screws 18 at one end and is provided with a flange 19 at the other end, which flange, in turn, is riveted to the hanger plate 7. Similarly riveted to the opposite end of the hanger plate 7 is a flange 21 of a second plate 20, for supporting the second side of the tension devices, which plate 20 is formed with a right angle wall 20a, Figure 5, this wall also being'provided with'a flange which is riveted to plate 17 and is secured to the longitudinal plate 6 of' the frame 3 by means of the screws 18. It will be seen that the supporting plates 17 and 2O together with hanger plate 7 form a box support and enclosure for the counterbalancing tension devices, which, in

the specific form exemplified in Ythe draw- Y ings, consist of spring-controlledv drums 22 and 23. Each plate 17 and 2() is formed with `a pair of raised portions which in turn are provided with slots 24 semi-circular at their there-.fore be necessary to describe only oneV of them. I

Each drum 22 and 23 is mounted on a hol to :the distance between the outside faces of the plates 17 and 2O when assembled, as shown in Figure 5.

Each drum is likewise provided with side vflanges 27 and with a cylindrical 'body portion 2 8, Figure 7, this cylindrical portion 28 being formed of a single plate rolledto cylindrical shape. extending through slots in ,the flanges 27,

these tongues being slightly riveted over tor rigidlysecure the parts of the kdrum together.

`The cylindrical portion 28 is so formed that a small open space or slot29, Figure '9, re-

ina-ins between the abuttingends of this cylini drical portion. ih fiat'spiralspring 30 has one .end provided with a hook 31 which'k is adapted to fit into the slot 29 and the other end of said spring. is similarly provided with a hook 32 which projects into a\slot 33 in the axle 26. Each of the side flanges 27 yof the i' `vdrum is 4provided with a hub 34r rotatably mounted on the axle 26. A -recess 35 is formed in each end of the axle 26. This re- This plate is provided with tongues y ao.r

cess, it will be understoodds cut through both Vwalls of the axle in a direction at right angles i' -to the axis. The width of the recess is the saineas the vwidth of the `tongue V25 in plates v17 and 420. The depth of each recess is ypret!r erably equal to the thickness ot one ofthe These end ings 37 to permit the plate to slide ever-the projecting portions of the axle and these v end "f l" plates are' also formed with a bar 3810i the l same width as the tongue ot plates 17 and 2O which bar is adapted to slide into the recess in the end ofthe axle. One ot these plates 36 is mounted uponeach end of the axle 26 and the two plates arethereatter screwed or otherwise secured against displacement by means of the screwor other fastening means 39. It will be understood that the bars 38 l., limit the inward movement of the end plates 36 bystriking against the bottom of therecess 35, and it will also be understood that the bottoms of the recesses are spaced from the Y n ends of the axle 26 a distance slightly greater lit - than the over-all width of the hubs 34 on the drums 22 and 23, in order that the drums may be tree to rotate.' It will be understood that each assembly consisting of a drum 22 or 23, axlev26, end plates'36 and screw 39, forms a unit'and can easily behandled without coming apart. It will be noted that the axle projects beyond the end plate 36 on each end an amount equal to the thickness of the side plates 17 and 2U.

This assembled drum unit isadapted to be lowered into place by 'sliding the projecting ends of the axle 26 into the slots 24 and causing the recesses35 to register with the tongues 25 in the plates 17 and 20. After beingthus located the end plates 36 are secured to the plates 17 and 20` by means of screws 40 for which suitable holes are tapped in the end plates 36 andprovided in the support plates v17 and 20. It lwill also be noted that these transmitting the load to the frame 3.

` As'statecl above, one of these sets of drums v is mounted at each side of the opening 2 adjacent the side plate member 17, A round bar 43 extends from the plate 20 on one side ofthe opening to the corresponding plate 2O on the other side of thevopening. This bar is suitably secured vto the plates 20and thus serves as a spacing member to properly space the two support plate units. This bar 43 serves as an axle for two rollers 44 which are rotatably mounted on said -bar and which serve as rolling supports for the stairway, as will be hereinafter described'.

- Two steelcables or other flexible members 45 are secured to thegdrums 2,2 in any suitable manner and lead from the top of these drums to,k pulleys 46 mounted in brackets 47, which,

in turn,-are supported" on the trame 3, as clearly shown 1n Figures 1 to 4 inclusive. To

' the opposite end of each of these cables is secured va bracket 48 rotatably supporting a grooved pulley 49. This pulley is adapted to run on the round equalizing bar 50 which, in turn, is connected by means ot two brackets 51 with the panel 15. It will thus he seen that the lowering of the panel from the position shown in Figure 3 to that shown in Figure 1, which can be conveniently done by pulling on they hand-chain 52, will cause the spring 30 inside of the drum 22 to wind up and therefore increase its tension. Likewise, it will be seen that the tension of this spring 30 will cause the panel 15 to rise to the closed position shown in Figure 3 as soon as the tension ot the spring is greater than the weight ot' the panel and its superimposed load. It will also be noted that a lugforstop 53, which is made in two halves and is adjustably clamped on each of the cables 45, Figures 1 and 2,. serves to stop the panel 15 in the r" desired loweredposition by striking against the ear 54 on the bracket 47. It should likewise be noted that the grooved pulley 49 travels from the right-hand position shown in Figure 1 to the left-hand position shown in .i

Figure 3 the panel 15 is lifted toward the ceiling, which will be clearly evident from the drawings and which need not be further referred to here as it forms the subject matter ot another patent application.

Suitably secured to the drums 23 are two steel cablesv or other lexible members 55 which run :trom the bottom ot these drums. The other ends of these cables are anchored b y means of brackets 56 to the steel stairway 57. This steel stairway consists of treads 58 supported on angles 60, hand-rail 59, suitable bracing 60 and two angle stringers 61. as shown in Figures 1 to 4, Figure 7 and Figures 14 to 18. As shown, these angle stringers are arranged with one iiange horizontal and the other flange vertical. Mounted on the panel 15 Lare two brackets 62, leach of which supports a roller 63.y These rollers, together with the rollers 44 previously referred to, support the Stringer angles 61, these rollers 63 and 44 being properly spaced laterally so that the horizontal langes of the stringer angles 61 will run on top of the rollers, and the verticalflanges ot the Stringer t angles will serve as lateral guides.

Special guides are provided to guide the stairway and to prevent the stairway stringers from jumping oil' the rolling supporting wheels 44 and 63, which willnow'be described.

As shown in Figures 14, 15 and 16, lthe wheels 44 are mounted on shaft 43. Inside of and adj acentr to each wheel 44 'is mounted a pivoted guide bracket 64,y which is pivotally mounted on yshaft 43,l and the upperend lof which is substantially the same diameter as the wheel 44. These bracketsr are connected by au bar v whichiis provided `with| aA right angle bendateach'nd and issecurdto each pivoted guide bracket 64 by a rivet 65. This A bar 65l provided so that the'l pivoted guide 4face ofthe hub is held in position by means ofI the split cotter pin 66, mounted in the Shaft 43, this arrangement insuring the proper location of the wheels 44 on the shaft 43.

Each wheel 44' supports the horizontal flangefof one of the Stringer angles 61 and thisstringer angle is thereby prevented from moving downward. In order to prevent the Stringer angle from jumping upward, the pivoted guide bracket 64vis provided with a flange 67 alt the top which projects out-I wardly over the horizontal flange ofthe Stringer angle 61, thus preventing the Stringer angle from jumping upward. It will be understood that this flange 67 normallly has sliding engagement with the horizontal flange of thel Stringer angle 6l. Be-

low the flange 67. is provided the flange 68 of an angle which is riveted to the pivoted guide bracket 64 by means of the rivets 65a and 64a. This angleis so located that its flange 68 will be in sliding engagement with the underside of thestringer angle 61. The flanges 67 and 68 thus serveas a guide in which the horizontal flange of the lStringer angle 61 slides.

.Referring to Figure 14, the upper ktread Y 58a is supported by two angles 69a, only one of which is shown in this figure. `These angles 69'@v are connected by bolts 70 and 71 to the Stringer angles 61 and longitudinal i member 7.2y of the stairway. Riveted to these angles 69?1L by means of rivets 69D is a stop angle73. which is provided with projecting flanges 74. These flanges 74 move up and down with thestairway and thus move :away from and toward the pivoted guide bracket-s 64 as the stairway is raised or lowered. It will bey noted that the flanges 67 on the pivoted `guide brackets 64 intersect the path of movemay be. replaced,- .Ixl arder t0 facilitate the threading of the horizontal flange of the Stringer angle 61 between the flanges 67 and 68,l the flange 68 is mader slightly longer than the flange 67, as is shown in Figure 14.

Referring now to Figures 17 and 18, it will be noted that theY horizontalflanges of the Stringer angles 61 ride on the rollers 63 which in turn are-supported in the brackets 62. One j Side of the hub of each of these rollers 63 contacts with a bracket 62 and the-other side is in contact with a cotter pin 75, the roller being thus guided laterally and definitely fixed with relation to therbracket 62 which, in turn, is riveted` to the panel k15. Pivotally mounted on a pin 76 at the up er end of the bracket 62 is an angle member v7 provided with al flange7 8. This flange 78' projects above the horizontal flange of the Stringer angle 61, as is clearly shown in Figure 18. The' roller 63 prevents the Stringer angle 61 from moving downward with relation to the `panel and the Vhorizontal flange 68I prevents the Stringery angle fromv accidentally jumping off this roller 63. flanged angle 7 7 is pivoted so that the flange 78 will not bind on the horizontal flange of the Stringer angle 61 as the stairway assumes slightly, different angles in the raising and lowering- Y y The extension of the stairway on the panel from the position shown in Figure 3 to that shown in Figure 1 `will cause the springs 30 inside of the drums 23 to wind up and thus increase their tension, and thusincrease the pull of the drums when'the stairway is in its This nearest approach to the vertical position at which timeiteXerts its greatest pull on the cables 55-55. Itwill be understood that the strength of the tension ofthe springs 30 in the drums 23 will be so selected that this tension will' practically counterbalance the Weight of the stairway in itsY different positions so that the stairway can be reciprocated on the rollers 63 and 44 by the operator with slight physical effort, the weight of the stair structure when extended slightly overcoming the counterbalancing force so that the Stairway will retain its position of use until retracted. e

It will be evident that it is possible to separately adjust the tension exerted by any one of the four drums byremoving the assembled drum unit from its seat in the support plates k17 and 20, rotating the drum one-half revolution, one revolution, or as manymore revolutions as may beneceSsary and replacing the drum. The rotation ofthe-drum will cause f the spring to be put under a greater or less tension depending upon the direction in which the drum is rotated. It will also be evident that the aXle 26 is locked against rotation due to its engagement with the bars 38 on end plates 36 and tongues 25 on plates 17 and 20.` For reasons of economy in the use of material, the suppertplates 17- and 20 are mail@ much as these plates 36 and 17 and 2O are Y under heavy tension.

of as thin material as possible and still insure suiiicient strength. The thickness of this materialk is ordinarily not suii'icient to insuresatisfactory resistance to the greater intensityI of the stress transmitted by the axle 26 to these plates when the springs 3,0 are The addition of the plate 36 with its bar 38 provides the extra thickness required to properly support the axle and seeureit againstl rotation. Inasusually made of the same thickness of ma terial, it will be evident that the bearing of the shaft 26 in its support has twice the area with little additional expense for metal. The provision of the end plates 36 and theiry attachment to the support plates 17 and 2O will, also, prevent the spreading of these support platesat the axle.

In the construction, of stairways of this type, it is alwaysgdesirable to keep the opening 2 as small as possible for a given'vwidth of stairway, not only to save as much attic floor space as possible but also for reasons of economy in construction. It will be seen that theamount-of space occupied by the counterb'alancinghdr-ums in a lateral direction is not greater than the width of a single drum due to the tandem arrangement ofthe two drums on each side. y

Stairwayscf this general type have been made of wood for many years. However, the

building of a stairway of steel involves many `different yproblems than the construction of a wood stairway of this type, due to the different shapes of the materials used in the f construction and also due to the heavier yweights and 'other different features involved in thisconstruction, so that successful steel stairways of thetype described hereinvhave n been developed only after a long and careful seriesof experiments. e

The operation of this apparatus is very simple. Assuming that the stairway is in the lowered position shown in Figure 1, it is only necessary for the operator to slide the stairway 57 kupwardly `and to the right with relationto the panell, as shown in Figure l,

until the lower end of the stairway is in line with'the lower end of the panel l5. i This operation of'sliding the stairway upwardlyvis kmade, easy due to the pull of the drums 23 as explained above. This will automatically remove sufficient weight from the panel l5 so that the tension of the spring 30 in the drums 22 willfcause the panel with the retracted stairway toy assume the upper position shown in Figure 3. It'will be understood that the panel remains in this position until the operator again pulls the hand-chain 52: When the operatoripulls this hand-chain in order to lower the stairway, the steps outlined above take placein reversed order. It will be understood that the panel 15 V will stop in the vdesired lowermost position as `determined by the location of the stops 53 on the cables 45 and that the stairway will stop in the 4desired lowermost position as determined by the flanges 74 striking against the flanges 67. These last-named stops are so located that the upper tread 58L of the stairway will be level with the attic Hoor.

Having thus described my invention, what I do claim and desire to secure by Letters Patentis: y i

l. A movable stairway comprising, in combination with a ceiling-opening metal frame formed with upper and lower peripheral angle members, and end plates and side plates secured to and connecting said angle members; a pair of spaced hanger plates secured to one of said angle members adjacent one of said end plates; hinges vertically adjustably mounted upon said hanger plates; a steel'panel supported at one` end by said hinges; a pair of spaced box supports secured to said hanger plates and said side plates, respectively, each box support coniprising vertical side members secured respectively to the ends of said hanger plates at oneend and secured to said side plate at the other end, one of said side members being also secured to said upper angle member, one of said side members being formed with4 a right angle end portion, a pair of longitudinally-spaced vertical open-top slots being formed in each of said side members adjacent lsaid hanger plates, said side members being formed with upwardly-extended tongues projecting into said slots; a ypair of axle members formed with Lend recesses adapted to register with said tongues; end platessecured to said axle members, having web bars also adapted to it said axle recesses, and secured to said side plates; a pair of drums for of each pair of drums at one end,traversing said first-mentioned pulleys, and connected at their other ends to said second-mentioned r pulleys, respectively; a steel stairway; cables secured at one end adjacent the bottom of said stairway and secured at the other end to the other of each pair of drums, respec tively; a pair of rollers mounted upon said panel adjacent the lower end thereof, said stairway being longitudinally movable of said panel yupon said last-mentioned rollers and also upon said rollers mounted on said bar connecting said box supports; means for guiding said stairway; and means for preventing the latter from jumping od said rollers.

2. A movable stairway comprising; in `combination with a ceiling-opening metal frame; a pair ot spaced hanger plates securedto and adj acentone end of said frame; hinges vertically adjustablymounted' upon said hanger plates; a steel panel supported at axles vand at 'the other end to the sidewalls of said drums, respectively; a 'bar connecting said pair of lbox supports 'adjacentfsaid hanger plates; a pair of 'rollers rotatably mounted on said ba'r adjacent the ends 'thereof; a pair of pulleys rotatably mounted on opposite sides of said metal frame adjacent the end thereof opposite to said hanger lplates; pulleys movably secured to said panel; cables secured to one of each pair'of drums at one end, 'traversing said vfirst-mentioned pulleys, and connected at their other ends to said second-mentioned pulleys, `respectively; va steel stairway; cables secured at'one end adjacent the bottom or said stairway and secured at the other end to theother of each Ipair of drums, respectively; 'a pai-r of rollers mounted upon said panel adjacent the lower end thereof, said'stairway 'being longitudinally movable of'sa'id panel upon said last-'mentioned rollersI 'and also upon said'rollers mounted on said bar connecting said box supports; means for guiding said stairway; an'd means for preventing the'latter from `j umping off said rollers. f

3. `A movable stairway comprising, incombination'with a ceiling-opening metal frame; a pair of spacedhanger plates 'secured to and vadjacent' one end of vsaid frame; Vhinges mounted upon said hanger plates; :a steel panel 'supported at one end by'said hinges; a pair of spacedbox 'supports securcd'to said hanger plates andthe `sides of said ltraine, respectively; a pair'ot longitudinally-spaced verticalopen-top slots being formed in each of said box supports; the latervbeing-formed with 'uuwardly-extended tongues projecting into said slots; a pair'orn axlemembersformed :with 'end recesses adapted to Iregister with rsaid tongues; 'means forsecuri-ng said axle members to fsaid 1boxsupports; a pair of 'drums for -ea'chbox housing having hubpo'rtions rotatably mounted on said axles; 'coifl springs secured at one end to each of said axles and at the other end' to the sidewalls of said drums, respectively; 'rollers rotatably mounted on said box supports; pulleys rotatably mounted on said metal frame adjacent the end thereof opposite to said hanger plates; pulleys movably secured to said panel; cables secured 'to one of each'pai'r of 'drums at lone end, traversing said iirstr mentioned pulleys, and connected at ytheir other ends to said second-mentionedpulleys, respectively; a steel stairway; cables secured at one end adjacent v'the bottom of'said l bination with a cei'linglopening metal 'ii-rame Y a pair o'ffsp'a'cedhanger plat'e's's'vecurec'l toan'd y adjacentv one end of 'said irame; hinges mounted upon said 'hanger'platesg a steel panel supported at one end bys'a'i'd hinges; `two .j pairs "of axle Fmembers; 'inea'nfs 4.for mounting Ithe latterv in "said ytranne with leach pair in tandem varrangemeiit; drumshaving 'ao y coil springs*securedatdne endto each of 'said axe-les Aand 1at Ithe other end 'to the Iside V'walls of said drums, frespectiv'e-ly gfro'lle'rs? rotatably stairway; cables secured Vat'on'e Iendladjacent thebottomof said stairway 'and secured at the -other end jto jthe other of leach pair of drums, respectively; rollers "mounted upon said Ypanel adjacent the lower end thereof, 1 Y

said stairway being 1longitu'dinally JAmovable of said panel upon Asaid last-mentio'ned'rollers 'and also up'ouf'said rollers mounted'on Y said frame; an'dm'e'ans'for gu'iding said-'stairway. i Y Y 5. A movable stairv'vayl comprising; v"avceiling support; a'panelthingedlymountedtheref on; V'rollers mounted 1i-pon sa-id supportjand j yrollers mounted upon 'sald'f'p'aneh'a stairway rmounted Yon said rollers and longitudinally movable thereove'r; twofpai-rsfofdrums independently --removably `mounted "on 'said support; cables connectingtwo of said drums and'opp'osite sides of's'aid 'pa-nel "cablesfc'onposite sides of said stairway; and spring tension devices adapted to be wound more tightly by the lowering of said panel, the tension 'of said spring devices being substantially mounted in tandem adjacent the two sides of said support; cables connecting one of the drums on each side and opposite sides of said panel; cables connecting the other two ot said drums and opposite sides of said stairway; spring tension devices mounted within the irst of said pair et drums and adapted to be wound more tightly by the lowering of said panel; and means for independently removing and adjusting and replacing said first pair of drums to secure the desired spring tension;

j 7L A movable stairway comprising, in combination with a ceiling-opening metal frame; a pair of spaced hanger plates secured to and adjacent one end of said frame; hinges mounted upon said hanger plates; a steel panel supported at one end by said hinges; two pairs of axle members; means for mounting the latter in said frame with each pair in tandem arrangement; drumsr having hub portions rotatably mounted on said axles; coil springs secured at one end to each of said axles and at the other end to the side walls of 'said drums, respectively; rollers rotatably mountedupon said frame; pulleys rotatably mounted upon said frame adjacent the end thereof opposite to said hanger plates; pulleys j movably secured to said panel; cables secured toone of eachpair of drums at one end, traversing said first-mentioned pulleys7 and connected at their other ends to said secondmentioned pulleys, respectively; a steel stairway; cables secured at one end adjacent the bottom ot said stairway and secured at the other end to the other of each pair of drums, respectively; rollers mounted upon said panel adj aeent the lower end thereof, said stairway being longitudinally movable of said panel upon said last-mentioned rollers and also upon said rollers mounted on said box supports; means for guiding said stairway;

means for adjustably limiting the amount ot panel movement; and means for limiting the amount of stairway movement.

8. A disappearing stairway for a ceiling opening comprising a panel hinged at one end of said opening; a stair structure carried by the panel and extensible and retractible thereon; means comprising a spring drum and cable thereonL connected to the panel substantially to counterbalance the panel and the stairway when retracted; means comprising a spring drum and cable thereon connected to the stair structure substantially to counterbalance the stair structure when the panel is open, said spring drums being located in said ceiling opening adjacent the panel hinges; and means located toward the other end of the opening over which the cable connected to the panel is trained.

9. A disappearing stairway for a ceiling opening comprising a panel hinged at one end of said opening; a stair structure carried by the panel and extensible and retractible thereon; means comprising a spring drum and cable thereon connected to the panel substantially to counterbalance the panel and the stairway when retracted; and means comprising a spring drum and cable thereon connected to the stair structure substantially to counterbalance the stair structure when the panel is open.

10. A disappearing stairway including a ceiling panel adapted to open and close a ceiling opening; a stair structure extensible and retractible on said panel; means for substantially counterbalancing the panel and Stair structure when the stair structure is retracted on the panel; and independent means substantially to eounterbalance the stair structure when the panel is open.

ll. A disappearing stairway for a ceiling opening comprising a panel hinged at said opening to open and close the same; a stair structure carried by and extensible and retractible on the panel; means for substantially counterbalancing the panel and stair structure and adapted slightly to overbalance the same when the stair structure is retracted on the panel so as to normally hold the panel shut, said means being adapted to be overcome by extension of the stair structure when the panel is open; and means for substantially counterbalancing the stair structure when the panel is open, said means being adapted to be slightly overbalanced by the stair structure so as to tend to hold the stair` structure extended.

Signed by me this 8th lday of February7 FRANK E. BESSLER. 

